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HVLP Sprayers?

11-30-2008, 01:55 AM

I have never used a sprayer before, but I just bought a HPLV spraygun at HF. But after looking through old issuses of WWJ (June 2007) I read the HVLP Spray Gun Shoot out and all the guns they tried have a compresser that comes with the gun. The one I bought has the tank on the top unlike the ones on the bottom. The question I have is, can't I use my shop air compresser with my gun if I turn down the presser? I thought I had read here of someone getting one from HF. Any help would be great. I don't think I want to start using this thing without knowing more info. Thanks

After I posted my question, went ahead and looked at other searches for spray guns. Still not sure if this gun only needs my air comresser (Craftsman 1 HP 3 Gal 125 PSI) I only want to use stain and Poly with it for now. I read that the waterbase poly is better because of the cleanup/smell. Alot of the posts I read said they have an air compresser but not much about the size needed for my use. Again any help would be nice. Thanks

Comment

After I posted my question, went ahead and looked at other searches for spray guns. Still not sure if this gun only needs my air comresser (Craftsman 1 HP 3 Gal 125 PSI) I only want to use stain and Poly with it for now. I read that the waterbase poly is better because of the cleanup/smell. Alot of the posts I read said they have an air compresser but not much about the size needed for my use. Again any help would be nice. Thanks

Comment

I believe what you are talking about are turbine sprayers. Instead of a compressor they bring a blower that works sort of like a vacuum in reverse. Some prefer this to the compressor type since it's portable. Compressor guns are best suited to shops since they ideally require a large compressor.

Your compressor however is too small. You can use it for very small projects with a gun with low air requirements but it's going to run continuosly and you might need to wait for it to catch up.

Comment

You guys hit it right on the head. The same gun and compresser. Or close enough. So, ether I go to spray cans to do some projects like turned legs, or BUY A LOT BIGGER COMRESSER. He He, I always wanted a bigger compresser. Hope the wife understands. (grin)

Comment

HVLP means High Volume Low Pressure, and they are talking about the air going to the gun. HVLP guns usually require 8 to 10 cfm at up to 50 psi to operate correctly.

Even some conventional spray guns require 8 cfm.

If you are spraying water-based, you will also need a larger fluid tip and a larger air cap with more atomizing air to get a decent spray. Water does not atomize as easily as petroleum solvents.

If you are spraying lacquer or shellac, you can get by with a lot less air than spraying water-based, and if spraying oil-based paints or varnish, you can thin them down to use less pressure, but that does not work with the water-based. Still, any compressor less than 7 or 8 cfm will make it difficult to spray anything large.

Also, if using a regular compressor with HVLP, you will want at least 3/8"id air hose until you get almost to the gun. 50' of 1/4 hose will not allow enough volume of air to supply an HVLP, even at 100 psi at the compressor.

Use an oil-water separator in line with your spray hose, and use a hose dedicated to only spraying, that is only hooked up to the separator so that no water or oil from the compressor contaminates the hose. Otherwise you may end up with fish-eye defects in the coating.

If spraying oil based on spindles, etc, you can probably get by with what is called a "touch-up" spray gun. It is smaller than a regular gun, takes a lot less air, but does not put out as large a spray pattern. However, it is much better than a spray can, and you can do many furniture items with it, especially the inside and tight areas.

This is often on sale for $79.99 and it has its own blower / turbine unit thing. It's an entire HVLP

I have one, but I haven't used it yet, so I can't speak to its quality or the results. But the reviews on Rockler are quite positive.

Just an aside, spraying water based is much safer, especially in an enclosed area. Oil based spraying can introduce a very serious explosive risk... Water based is still risky to your health, but not nearly so combustible / explosive.